Middle distillate

ABSTRACT

Middle distillate of improved pour point containing a pour point depressant concentration of the amidization reaction product of N,N-dialkylamine having 16 to 18 carbon atoms in each alkyl and hydroxy-containing carboxylic acid having 2 to 22 carbon atoms.

United States Patent [1 1 Gaydasch ]*Apr. 15, 1975 MIDDLE DISTILLATE[56] References Cited [75] Inventor: Alexander Gaydasch, Chicago, 111.UNlTED STATES PATENTS A z 1 2,622,018 12/1952 White et al. 44/66 UX [73]Sslgnee 32:33: 2 fi Company 2,898,301 9/1959 Mayhew et a1 260/56l B3,473,902 10/1969 Eckert 44/71 Notice: The portion of the term of this Pq to g- 1, 1989, Primary ExaminerDaniel E. Wyman has b en lsc lmAssistant Examiner- -Y. H. Smith [22] Filed: N0 16 1970 Attorney, Agent,or FirmJames R. Hoatson, Jr.;

Bernard L. Kramer [2]] Appl. No.: 90,068

Related U.S. Application Data [57] ABSTRACT Continuation-impart of 3March 9, Middle distillate of improved pour point containing a 1970,3,681,038- pour point depressant concentration of the amidizationreaction product of N,N-dia1ky1amine having 16 [52] U.S. Cl. 44/66 to 18carbon atoms in each alkyl and h [51] Int. Cl ClOl l/l8 containingcarboxylic acid having 2 to 22 carbon [58] Field of Search 44/66, 71;252/515 A; atoma 10 Claims, N0 Drawings MIDDLE DISTILLATE CROSSREFERENCE TO RELATED APPLICATIONS This is a continuation in part ofapplication Ser. No. 17,860 filed Mar. 9, 1970, now US. Pat. No.3,681,038.

BACKGROUND OF INVENTION Middle distillates are defined as petroleumdistillates containing components boiling above the range of gasolineand having an end boiling point of not above about 750F., and are sodefined in the present specification and claims. In one embodiment themiddle distillate also may include components boiling within thegasoline range and, in this embodiment, the middle distillate will boilwithin the range of from about 250F. to about 750F. In anotherembodiment the middle distillate will have an initial boiling pointabove gasoline and thus will boil within the range of from about 370F.or 400F. to about 750F.

The middle distillate is a liquid mixture of hydrocarbons and, uponcooling, some of them crystallize to form a waxy precipitate. Thesecrystals become active centers for further crystallization, with theresult that the distillate congeals and loses its free flowingproperties. The temperture at which this occurs is defined as the pourpoint and is of importance to petroleum refiners and users of othe oilin order that the distillate may be pumped or syphoned readily fortransportation or use.

Various means have been proposed heretofore to improve the pour pointproperties of the middle distillates. In one method this has taken theform of additional processing steps at the refiners, such as solventextraction to remove the components believed to cause crystallization.In another method various additives have been proposed, originally basedupon those which have been found effective in lubricating oils. However,it has been found that pour point depressants which are satisfactory inlubricating oils are not generally effective in middle distillates.

DESCRIPTION OF THE INVENTION As hereinbefore set forth, the middledistillate will be within the boiling range of from about 250F. to about750F. Illustrative middle distillates include kerosene, fuel oil, dieseloil and other middle distillates used for combustion or as cleaning oilsfor cleaning metallic equipment. In another embodiment, the middledistillate is an electrical insulating oil which is used intransformers, circuit breakers, etc. In still another embodiment themiddle distillate may comprise a conventional hydraulic oil. In stillanother embodiment the middle distillate may comprise an intermediateoil which is awaiting further processing as, for example, light cycleoil from catalytic cracking which is being stored'or transported priorto recycle to the catalytic cracking or sent to another process.

Regardless of the particular middle distillate, it is readily apparentthat the distillate must be free flowing at all temperatures encounteredin the transportation, storage and use thereof. The pour pointproperties of the middle distillate are improved in accordance with thepresent invention by incorporating therein a particular reactionproduct.

Parent application Ser. No. 17,860 is directed to the use ofN,N-dialkylricinole amides as pour point depressants and demonstratesthe unique properties thereof to lower the pour points of middledistillates. Now it has been found that other hydroxy-containingcarboxylic acids may be reacted with the N,N-dialkylamine to form amixture 'of products containing a substantial amount of the amide andthat these reaction products are of high effectiveness as pour pointdepressants.

In one embodiment the present invention relates to a middle distillateof improved pour point containing a pour point depressant concentrationof the amidization reaction product ofa N,N-dialkylamine having 16 to 18carbon atoms in each alkyl and a hydroxy-containing carboxylic acidhaving 2 to 22 carbon atoms.

In a specific embodiment, the present invention relates to fuel oilcontaining the amidization reaction product of N,N-ditallowamine andhydroxybutyric acid.

Based on an extensive research study, it appears that theN,N-dialkylamine containing chiefly 16 to 18 carbon atoms in each alkylis unique as a reactant in forming the improved reaction product withthe hydroxycontaining carboxylic acid. Also, as will be demonstrated inthe appended examples, the hydroxycontaining carboxylic acid offersexceptional advantages for use as a reactant in preparing the reactionproduct.

The reaction product will contain a substantial proportion of the amide,resulting from the reaction of the amine and acid. However, the reactionproduct also may contain an ester, which apparently is formed by theesterification reactions between hydroxyl group of acyl alkyls andcarboxylic group of the acids. In addition, the reaction product maycontain some salt and unreacted amine or acid which may result from theuse of an excess of stoichiometric amounts. F rom a practicalconsideration, the pour point depressant must be marketed at acomparatively low price. Accordingly, the economics do not warrant thefurther time and cost necessary to insure complete reaction to the amideand/or in isolating a substantially pure amide product, especially sincethe amide reaction product formed under less expensive conditions ishighly effective for the purpose.

As hereinbefore set forth, exceptionally good results have been obtainedwhen using a N,N-dialkylamine having 16 to 18 carbon atoms in each alkylas a reactant in preparing the reaction product. While the reactionproduct prepared from other N,N-dialkylamines do possess some pour pointdepressant properties, the effectiveness thereof is considerably lowerthan the reaction product prepared from the dialkylamine having 16 to 18carbon atoms in each alkyl.

In a preferred embodiment, the N,N-dialkylamine for use as a reactant isN,N-ditallowamine and more particularly hydrogenated N,N-ditallowamine.The N,N- ditallowamine predominates in alkyl groups containing 16 to 18carbon atoms, although it may contain a minor amount of alkyl groups of14 to 20 carbon atoms per molecule. The N,N-ditallowamine and thehydrogenated ditallowamine are available commercially and advantageouslyare used in preparing the reactant product.

While the N,N-ditallowamine is preferred because of ready availabilityand comparatively low cost, it is understood that other suitableN,N-dialkylamines may be used. In a preferred embodiment illustrativeexamples include N,N-dihexadecylamine, N,N- diheptadecylamine,N,N-dioctadecylamine and mixtures thereof. Conveniently the alkyl groupsare derived from fatty acids as in N,N-dipalmitylamine, N,N-distearylamine and mixtures thereof, or from the correspondingunsaturated fatty acids followed by hydrogenation. It is understood thatthe differently substituted amines are not necessarily equivalent foruse in forming the reaction product.

As hereinbefore set forth, the N,N-dialkylamine is reacted with ahydroxy-containing carboxylic acid having 2 to 22 carbon atoms.Illustrative acids include hydroxyacetic acid, hydroxypropionic acid,hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid,hydroxycaprylic acid, Hydroxypelargonic acid, hydroxycapric acid,hydroxylauric acid, hydroxymyristic acid, hydroxypalmitic acid,hydroxystearic acid, hydroxyarachidic acid, hydroxybehenic acid,hydroxydecylenic acid, hydroxystillingic acid, hydroxydodecylenic acid,hydroxypalmitoleic acid, hydroxyoleic acid, hydroxypetroselinic acid,hydroxyvaccenic acid, hydroxylinoleic acid, hydroxyeleostearic acid,hydroxyparinaric acid, hydroxygadoleic acid, hydroxyarachidonic acid,etc. In one embodiment, the hydroxyl group is attached to a terminalcarbon atom and, in another embodiment it is attached in the chain as,for example, in ricinoleic acid, lactic acid, etc. In still anothermethod the reaction product is prepared by the reaction of a precursorcompound as, for example, a lactone as illustrated bygamma-butyrolactone, gamma-valerolactone, etc.

The reaction product is prepared in any suitable manner. The reaction isconducted under conditions to effect substantial formation of the amideand is defined herein as amidization conditions or as the amidizationreaction product. This means that the hydroxyl group of the acid reactswith the hydrogen of the amine to liberate water. The temperature to beemployed will depend upon the pressure and upon the solvent whenemployed. At ambient pressure, the temperature may range from about175F. to about 450F. and correspondingly lower when effected undervacuum and thus may range from about 120F. to about 400F. In one methodthe reaction is effected by refluxing the acid and amine preferably inthe presence of a solvent. When utilizing benzene solvent, thetemperature may be in the range of from 170F. to 190F. With toluene, thetemperature may be within the range of from 225F. to 250F. With xylene,the temperature may be in the range of from 280F. to 310F. Withdiethylbenzene, the temperature will be in the range of 350F. to 400F.With n-dodecane, the temperature may be within the range of from 400F.to 450F. These are only typical temperatures utilized at ambientpressure and will vary with the particular pressure employed and also asto whether the solvent is a mixture of isomers and/or other compounds.

Any suitable solvent is used and includes aromatic hydrocarbons such asbenzene, toluene, xylene, ethylbenzene, diethylbenzene, cumene ormixtures thereof, paraffinic hydrocarbons such as n-heptane, n-octane,n-nonane, n-decane, n-undecane, n-dodecane, etc. or a mixture thereof,or a mixture of paraffinic and/or naphthenic hydrocarbons including someof the middle distillates such as diesel oil, No. 2 fuel oil, lightcycle oil or other mixtures.

The reflux zone preferably is equipped with heating means, stirringmeans and reflux condenser. In another embodiment the reaction iseffected in an autoclave, which is arranged to provide suitable mixing,heating and can be operated under autogenous, reduced or elevatedpressure.

As hereinbefore set forth, the reaction is effected under conditions toprepare a substantial proportion of the amide product. Accordingly, thetime of reaction will be determined by the amount of water collected,which then may be correlated with the amount of amide formed, allowingfor ester formation resulting from the interaction of alcoholic andcarboxylic moieties. The time of reaction may range from 4 to 50 hoursor more. The reaction preferably is effected using equal molarproportions of acid and amine, although an excess of one or the othermay be used to insure complete reaction. The reaction preferably iseffected in the presence of a catalyst and conveniently comprises aresino-sulfonic acid such as Amberlist 15. It is understood that anysuitable acidic catalyst may be used. In another embodiment,particularly when the reaction is being conducted in an autoclave, asmall amount of mineral acid and particularly hydrochloric acid may beused. In still another embodiment, the hydrochloride of the amine may bepreformed and the acidic catalyst introduced in this manner.

Following completion of the reaction, the products are worked up in anysuitable manner. ln one method the reaction products are filtered toremove the catalyst. The filtering may be effected an an elevatedtemperature and especially when the cooled product is solid at roomtemperature. Following removal of the catalyst, the product may becompletely evaporated to yield a solid salt but preferably is onlypartially dried to remove light volatile material. In many cases asolution of the product in the solvent used in the reaction medium ismore convenient for use because it simplifies incorporating the productinto the middle distillate.

The reaction product is incorporated in the middle niently compriseshydrocarbons, including aromatics such as benzene, toluene, xylene,cumene, etc., or paraffins including decane, undecane, dodecane,tridecane, tetradecane, pentadecane, etc. but preferably comprises amixture such as naphtha, kerosene, middle distillate, etc. It isunderstood that the amide may be used in conjunction with otheradditives normally added to middle distillates, which additive will varywith the particular middle distillate and may comprise one or more ofantioxidant, corrosion inhibitor, cetane improver, dye, metaldeactivator, etc.

The following examples are introduced to illustrate further the noveltyand utility of the present invention but not with the intention ofunduly limiting the same.

EXAMPLE l N,N-ditallow-ricinoleamide was prepared by refluxing 15 g.(0.05 mole) of ricinoleic acid, 25 g. (0.05

mole) of N,N-ditallowamine in the presence of 200 g. of diethylbenzenesolvent and about 2 g. of Amberlist l5 resin. The N,N-ditallowamine ishydrogenated and available commercially under the tradename of Armeen2I-IT. This amine predominates in C ,C,,, alkyl groups. The mixture wasrefluxed at 362F. for about 13 hours. The water liberated in thereaction amounted to 0.9 cc. Following completion of the reaction, theeffluent products were filtered and evaporated in vacuo. There wererecovered 39.5 g. of product which contained 47% ofN,N-ditallow-ricinoleamide.

EXAMPLE II The reaction product of this example comprisesN,N-ditallow-hydroxyacetamide and was prepared by refluxing 50 g. (0.1mole) of Armeen 2I-IT and 8 g. (0.1 mole) of glycolic acid in 350 cc. ofxylene and 2 g. ofAmberlist l5" resin. The mixture was refluxed at 284F.for 24 hours, during which time 1.8 cc. of water was collected. Thereaction product was filtered hot and then dried to produce 52 g. ofproduct which contained 78% by weight of the amide.

EXAMPLE III The product of this example comprisesN,N-ditallowhydroxypropionamide and was prepared in substantially thesame manner as described in the previous examples. In this preparation;a mixture of 50 g. (0.1

mole) ofArmeen 2HT", 11 g. (0.1 mole) of 85% lactic acid, 205 g. ofdiethylbenzene and 2 g. ofAmberlist l5 resin was refluxed at 358F. for l1 hours, during which time 6 cc. of water was collected. The productcomprises 54 g. of a light tan solid.

EXAMPLE IV EXAMPLE V Additional reaction products were prepared insubstantially the same manner as described in the previous examples byreacting Armeen 2HT separately with caprolactone and hydroxystearicacid.

EXAMPLE VI The reaction product comprising N,N-ditallowricinolamide alsowas prepared by reacting 0.05 moles Armeen 2HT with 0.05 molesricinoleic acid in toluene solvent. This reaction was effected in a 1000cc. rocking autoclave at 392F. for 6 hours.

EXAMPLE VII The reaction product comprising N,N-ditallowricinolamide,prepared as described in Example I, was evaluated as a pour pointdepressant in three middle distillates as follows.

Middle distillate A is a commercial No. 2 fuel oil having an initialboiling point of 428F., an end boiling point of 677F. and a pour pointof F.

Middle distillate Bis a light cycle oil from a commercial catalyticcracking unit. This distillate has an initial boiling point of 397F., anend boiling point of 650F. and a pour point of 10F.

Middle distillate C is a commercial diesel fuel oil having an initialboiling point of 377F., an end boiling point of 655F. and a pour pointof 5F.

The pour points were determined by ASTM D97-57 method, which is astandard method for such determinations. The results reported in thefollowing table are on the basis of the pour point depression, which isthe difference between the pour point of the blank or control distillate(without additive) and the pour point of the distillate containing theadditive, reported in F.

The amide was incorporated in the middle distillate in a concentrationof 1000 ppm (parts per million).

TABLE I Middle Pour Point Test No. Distillate Depression. F.

1 A 50 2 B 40 3 C 45 From the data in the above table, it will be seenthat the ricinoleamide was very effective in depressing the pour pointsof all of the middle distillates. This high effectiveness in each of thethree different middle distillates is unusual and demonstrates theunique effectiveness of the ricinolamide as a pour point depressant.

EXAMPLE VIII The reaction products prepared according to Examples II,III, IV and V also were each separately evaluated in a concentration of1000 ppm in the middle distillates described in Example VII.

The results of these evaluations are reported in the following table.

From the above data it will be seen that the reaction products preparedin accordance with the present invention were very effective pour pointdepressants in middle distillates A and B. Except as noted in the table,the reaction products were of substantially no benefit in middledistillate C. However, the amides prepared from hydroxybutyric and fromhydroxystearic acid and also from ricinoleic acid (Example VII) werevery effective in middle distillate C.

EXAMPLE IX A number of corresponding amides were prepared by using theacid as reactant instead of the hydroxy acid. These amides were preparedin substantially the same manner as described in the previous examplesand also were evaluated in the same manner as described in Example VII.

The results of these evaluations are reported in the From the data ofthe above table, it will be seen that the amide prepared from theseacids not containing the hydroxy] substituent were of substantially noeffectiveness as pour point depressants. In contrast, as seen by thedata in Example VIII, the corresponding reaction products from hydroxyacids or precursor were very effective pour point depressants.

I claim as my invention:

1. Middle distillate of improved pour point containing in combinationtherewith a pour point depressant concentration of the amidizationreaction product of N,N-dialkylamine having 16 to 18 carbon atoms ineach alkyl and hydroxy-containing carboxylic acid in which hydroxylgroup is attached to the terminal carbon atom, said carboxylic acidhaving 2 to 22 carbon atoms.

2. The middle distillate of claim 1 in which said reaction product ispreparedby reacting at a temperature of from about F. to about 450F. fora time of from about 4 to about 50 hours.

3. The middle distillate of claim 1 in which said N,N- dialkylamine isN,N-ditallowamine.

4. The middle distillate of claim 1 in which said N,N- dialkylamine ishydrogenated N,N-ditallowamine.

5. The middle distillate of claim 4 in which the reaction productcomprises N,N-ditallowhydroxyacetamide.

6. The middle distillate of claim 4 in which the reaction productcomprises N,N-ditallow-hydroxypropionamide.

7. The middle distillate of claim 4 in which the reaction productcomprises N,N-ditallowhydroxybutyramide.

8. The middle distillate of claim 4 in which the reaction productcomprises N,N-ditallowhydroxycaproamide.

9. The middle distillate of claim 4 in which the reaction productcomprises N,N-ditallowhydroxystearamide.

10. The middle distillate of claim 1 in which said concentration is fromabout 0.001% to about 1% by weight.

1. MIDDLE DISTILLATE OF IMPROVED POUR POINT CONTAINING IN COMBINATIONTHEREWITH A POUR DEPRESSANT CONCENTRATION OF THE AMIDIZATION REACTIONPRODUCT OF N,N-DIALKYLAMINE HAVING 16 TO 18 CARBON ATOMS IN EACH ALKYLAND HYDROXYCONTAINING CARBOXYLIC ACID IN WICH HYDROXYL GROUP IS ATTACHEDTO THE TERMINAL CARBON ATOM, SAID CARBOXYLIC ACID HAVING 2 TO 22 CARBONATOMS.
 2. The middle distillate of claim 1 in which said reactionproduct is prepared by reacting at a temperature of from about 175*F. toabout 450*F. for a time of from about 4 to about 50 hours.
 3. The middledistillate of claim 1 in which said N,N-dialkylamine isN,N-ditallowamine.
 4. The middle distillate of claim 1 in which saidN,N-dialkylamine is hydrogenated N,N-ditallowamine.
 5. The middledistillate of claim 4 in which the reaction product comprisesN,N-ditallow-hydroxyacetamide.
 6. The middle distillate of claim 4 inwhich the reaction product comprises N,N-ditallow-hydroxypropionamide.7. The middle distillate of claim 4 in which the reaction productcomprises N,N-ditallow-hydroxybutyramide.
 8. The middle distillate ofclaim 4 in which the reaction product comprisesN,N-ditallow-hydroxycaproamide.
 9. The middle distillate of claim 4 inwhich the reaction product comprises N,N-ditallow-hydroxystearamide. 10.The middle distillate of claim 1 in which said concentration is fromabout 0.001% to about 1% by weight.